Special Forces take part in an anti-terrorism exercise at the Olympic Stadium on Dec. 12. The drill was part of security preparations for the 2018 PyeongChang Winter Olympics in February. / Korea Times photo by Kim Joo-young

By Chyung Eun-ju, Park Si-sooSouth Korea has deported 17 foreigners in a preemptive anti-terror action before the PyeongChang Olympics in February, the immigration office said Tuesday.They were from five countries, including unidentified ones in Southeast and Central Asia, according to the Korea Immigration Service.They were either members of international terrorist groups specified in the country's Anti-Terror Law or those on a wanted list shared by a network of intelligence agencies. Detailed information about them was unavailable. "We have deported 17 foreigners who could potentially pose a terrorist menace to the Olympics," an immigration official said. "It was possible with the close cooperation and intelligence sharing of spy agencies in 50 countries." He did not elaborate, but said the government will spare no effort to make the Olympics a success. "We must be very thorough in counter-terrorism as athletes and people all over the world are coming to the PyeongChang Winter Olympics," he said."We don't rule out the possibility that foreign terrorists could enter (the country) by pretending to be Olympics travelers or hired workers at Korean companies. So we have to be vigilant before and during the Olympics." The government said it is collecting terrorist intelligence with 50 countries. Some countries are expected to send covert agents to protect their athletes and staff during the Olympics. For its part, South Korea has conducted anti-terror drills with hundreds of armed police officers and firefighters in and around the Olympics venues in PyeongChang and Gangneung. During the Games, about 5,000 armed forces personnel will guard venues around the clock.